Methods and devices for treatment of bone fractures

ABSTRACT

A method and devices for facilitating fixating and joining of bone fractures utilizing expandable devices that are positioned within the bone and across the fracture site. The stress from the expanded may enhance and expedite bone healing.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] I claim the benefit of provisional applications with Ser. No.60/169,778, 60/181651 and 60/191664

FIELD OF INVENTION

[0002] The present invention relates generally to the treatment of bonefractures utilizing expandable fracture fixating devices within themedullary cavity of bones, and equipment and methods specially designedfor implanting these devices.

BACKGROUND OF THE INVENTION

[0003] The current methods of treating bone fractures ranges from simplesetting of the bone and constraining motion via a cast or wrap to usingpins, screws, rods and cement to fixate fracture site. With the use ofcasts, the bone is not stabilized and misalignment may occur afterplacing the cast. This may require the cast to be removed and the bonereset. This is a very uncomfortable and painful procedure for the victimand can ultimately result in permanent misalignment of the healed bone.The treatment modalities requiring a surgical procedure are painful andare associated with a high rate of complications. Post-proceduralinfections are one of the major complications associated with thesesurgical procedures. Many of these infections result in necrosis of boneand tissue and require additional surgical interventions and therapy.The invention discussed here provides for a unique and novel means oftreating a variety of bone fractures with minimally invasive techniquesand low complication rates.

SUMMARY

[0004] In contrast to the prior art, the present invention proposestreatment of bone fractures using minimally invasive techniques,methods, equipment and devices to position and deliver an expandablefracture fixating device into the medullary cavity(marrow conduit). Thedevice is preferably an expandable structure that “bridges” the fracturesite and fixates the site upon expansion. In addition to fixation, thedevice also joins the fractured bone such as in the case of a compoundfracture. Referring to the device as a bridge, the BRIDGE issubstantially hollow and has low surface area and mass, the majority ofbone marrow volume can be preserved. The ability to preserve a largequantity of the bone marrow cavity is beneficial for healing, bonehealth and maintaining the body's natural ability to generate red bloodcells. In addition, the stress applied to the bone by the expanded orexpanding “BRIDGE” facilitates rapid bone growth and strength. Theoperable level of stress applied to the bone will vary from low levelsto high levels dependent on the type, size and location of bone to betreated. It is also envisioned that the BRIDGE can be used to expand andsupport bones that are crushed or compressed. The BRIDGE can bedelivered by a variety of expansion devices, can be self expanding todue to inherent spring forces within the BRIDGE structure, or can beexpansively actuated utilizing elements and mechanisms within the BRIDGEstructure. These various devices and alternative embodiments will bedetailed further.

[0005] Although standard medical equipment may be used to facilitate theprocedure, it may be necessary to design unique, specialized tools inorder for this invention to be properly utilized. These devices mayinclude tissue separators, retractors, drills, introducers, coringtools, and others.

[0006] The invention is disclosed in the context of treating bonefractures but other organs and anatomical tissues are contemplated aswell. For example, the invention may be used to treat spinal stenosis,individual vertebrae, and support or fixate segments of the spinalcolumn. Likewise, a broken nose, sinus cavity or collapsed lung can besupported using this invention. Pelvic fractures in females could alsobenefit from placing this device within the vaginal cavity in order tosupport and fixate the pelvis or pubic bone.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Throughout the several views of the drawings several illustrativeembodiments of the invention are disclosed. It should be understood thatvarious modifications of the embodiments might be made without departingfrom the scope of the invention. Throughout the views identicalreference numerals depict equivalent structure wherein:

[0008]FIG. 1 is a diagram showing the advancement and deployment of theBRIDGE utilizing a catheter with an expandable element

[0009]FIG. 2 is a diagram showing the advancement and deployment of aself-expanding BRIDGE

[0010]FIG. 3 is a diagram showing the advancement and deployment of theBRIDGE, utilizing a catheter with an expandable element, within acompressed bone segment

[0011]FIG. 4 shows a variety of acceptable BRIDGE structures and designs

[0012]FIGS. 5A & B depict a bridge that can be expanded or contracted byrelative movement of the ends of the structure

[0013]FIG. 6 shows a bridge that can be expanded or contracted byrelative movement of the ends of the structure

[0014]FIG. 7 shows a bridge that can be expanded or contracted byrelative movement of the ends of the structure

[0015]FIG. 8A & 8B show the placement of a coil BRIDGE

[0016]FIG. 9A & 9B show the placement of a braided BRIDGE

[0017]FIG. 10 shows the screws or nails used in conjunction with animplanted BRIDGE

[0018]FIG. 11 shows a BRIDGE used in conjunction with externalsupporting elements

[0019]FIG. 12A & 12B shows an implanted BRIDGE connected to anelectrical generator.

[0020]FIG. 13 shows an expansion device using a rubber grommet

[0021] While the invention will be described in connection with thepreferred embodiment, it will be understood that it is not intended tolimit the invention to that embodiment

DETAILED DESCRIPTION

[0022] Throughout the description the term BRIDGE refers to a expandabledevice that is used to fixate or repair bone fractures. The device maybe made of metals such as stainless steel, tantalum, titanium, Nitinolor Elgiloy and it may form an electrode for electrical stimulation. Oneor more electrodes may be associated with it. The BRIDGE may incorporatefiber optics for imaging, sensing, or the transmission of energy toheat, ablate, or illuminate. The device may also be made from a plasticor other non-metallic material. The BRIDGE may also incorporate acovering of polymer or other materials. The BRIDGE may also be acomposition of different materials. The BRIDGE may be smooth or havecutting or abrasive surfaces. The BRIDGE can be self-expanding or use adevice such as a balloon catheter to mechanically expand or furtherexpand it. In addition, other means of expanding the BRIDGE may beutilized such as any mechanical means of expansion, or thermal,vibrational, electrical, hydraulic, pneumatic actuation. Mechanicalmeans might employ a system consisting of a rubber grommet that expandswhen it is compressed axially. Another mechanical means of expansion mayuse a tubular array of elements such as splines, wires or braided wirethat expand radially outward when compressed at each end. Anothermechanical means could employ wedges in a tubular or cylindrical type ofarray that collectively force the BRIDGE to expand when they are movedrelative to each other. The BRIDGE delivery system may also employ fiberoptic technology in order to endoscopically diagnose, control placementand review procedural outcome. Likewise, a number of other technologiessuch as pressure monitoring, stress monitoring, volume monitoring, etc.can be employed to benefit the outcome of the procedure.

[0023] The BRIDGE may be implanted for chronic use or for acute use. Inacute use, the BRIDGE is used for temporary stabilization and fixationof bone fractures. After a period of time, the BRIDGE is withdrawn.

[0024] Biodegradable materials that degrade or dissolve over time may beused to form the BRIDGE. Various coatings may be applied to the BRIDGEincluding, but not limited to, thrombo-resistant materials, electricallyconductive, non-conductive, thermo-luminescent, heparin, radioactive, orbiocompatible coatings. Materials such as calcium, minerals, orirritants can be applied to the BRIDGE in order to expedite bone growth.Drugs, chemicals, and biologics such as morphine, dopamine, aspirin,genetic materials, antibiotics and growth factors can be applied to theBRIDGE in order to facilitate treatment.

[0025] Other types of additives can be applied as required for specifictreatments.

[0026] Electrically conductive BRIDGEs with electrode elements may beused with companion pulse generators to deliver stimulation energy tothe bone to expedite bone growth. This electrical therapy may be usedalone or in combination with other therapies to treat the affected site.Electrical therapies may be supplied from implantable devices or theymay be coupled directly to external generators. Coupling between theBRIDGE and external generators can be achieved using technologies suchas inductive or microwave coupling as examples. The BRIDGE may also bedesigned of geometries or materials that absorb radioactive energies forthe treatment of bone cancer, as an example.

[0027] In the preferred embodiment, access is gained to a location onthe bone that the device will pass through. A surgical incision is madethrough tissue to expose the entry site at the bone. The size and scopeof the incision is dependent on the need for each case, Preferably, asmall hole is drilled through the bone into the medullary cavity (marrowconduit). Larger holes or removal of a portion of the bone may berequired dependent on the need for each case.

[0028] In the example of a fractured femur, an access location might bethe either the greater trochanter or the patellar surface. In the caseof a fractured humerus, the access might be made at the greater tubercleor the capitulum.

[0029] The device, on its delivery system, is then passed through themarrow cavity and positioned across the fracture.

[0030] When the right position is attained (potentially guided by CATscan, MRI, x-ray, or fluoroscopic imaging), the fracture can bemanipulated to an optimum configuration if needed, and the device isexpanded or released for expansion. The delivery system is then removedafter expansion.

[0031] If necessary, the access hole in the bone can be plugged withretained bone chips from the drilling procedure, fibrin or otheracceptable materials.

[0032] Any surgical incision is closed with standard techniques.

[0033] It may be necessary to remove some bone marrow to facilitateplacement of the BRIDGE. After placement of the BRIDGE, the marrow canbe reinserted into the bone and within the BRIDGE. Another alternativetreatment may be to replace the marrow with a polymeric substance thathardens after placement within the bridge and bone portions. This wouldenhance the immediate fixation strength. The polymeric substance can bebiodegradable or otherwise metabolized by the body. In addition, thepolymeric substance may incorporate drugs, antibiotics other clinicallyrelevant substances and materials. The polymeric substance can also forma foam or cellular structure to allow for marrow formation.

[0034] Other embodiments of the BRIDGE invention can include the use ofexternal screws that join the BRIDGE through the bone. This provides andextra measure of securement and strength.

[0035]FIG. 1A is a diagram showing the BRIDGE 10, which is mounted to aballoon catheter delivery device 11 within a segment of fractured bone12. The entire system is advanced through an opening 13 in the bone 12.The BRIDGE 10 is positioned to span the fracture. At this point, theballoon is inflated causing the BRIDGE to expand against the inside ofthe bone. The balloon may be inflated via a syringe or pump 14 and apressure gauge 15. The balloon may have a pre-determined minimum ormaximum diameter. In addition, the balloon can have a complex shape toprovide proper placement and conformance of the device based onanatomical requirements and location. One or more inflations may be usedto insure proper positioning and results. FIG. 1B shows the expandedBRIDGE 10 spanning the fracture and connecting the bone segments. Thedelivery device 11 is being withdrawn. If required, the balloon may bereinserted and reinflated for additional BRIDGE manipulation.

[0036]FIG. 2A is a diagram showing a self-expanding BRIDGE 20, which iscompressed and inserted within a catheter delivery device 21, within asegment of fractured bone 22. The entire system is advanced through anopening 23 in the bone 22. The BRIDGE 20 is positioned to span thefracture.

[0037] At this point, the BRIDGE 20 is released from the catheter andself-expands against the inside of the bone. The release mechanism canbe simply pushing the BRIDGE out of a catheter lumen or retracting aretaining sleeve. The BRIDGE self-expands due to the spring forcesinherent in its materials and design. Likewise, the BRIDGE can be madeof a shape-memory material such as Nitinol so that when subjected tobody temperature the structure expands. With shape memory materials, theshape of the expanded device can be predetermined. Additionally, thedevice can be retrieved, repositioned, or removed by usingtemperature-based shape-memory characteristics.

[0038]FIG. 2B shows the expanded BRIDGE 20 spanning the fracture andconnecting the bone segments. The delivery catheter 21 is beingwithdrawn.

[0039] In the self-expanding case, the tubular mesh has a predeterminedmaximum expandable diameter.

[0040]FIG. 3A shows a BRIDGE 30 on a balloon catheter 31 being advancedinto a crushed area of a bone.

[0041]FIG. 3B shows the BRIDGE 30 expanded within the crush zone causingthe crushed bone to resume its original diameter. The same results canbe attained using any of the aforementioned BRIDGE designs, such asself-expanding or manually expanded, and placement methods. In the caseof self-expanding designs, further expansion of the BRIDGE can beperformed using a balloon catheter or another type of expansion devicesuch as those mentioned within this invention or can use solid dilatorrods.

[0042]FIG. 4 shows a variety of possible BRIDGE shapes and geometries. Atubular mesh 42, a multi-element spline 44, a coil 46, slotted tube 48,and a clam-shell or sleeve 49. In the case of slotted tube, othergeometric configurations of the slots (i.e.; hexagonal, sinusoidal,circular, meandering, spiraling, and multigeometric patterns) may beutilized alone or in conjunction with a combination thereof Likewise,variations in the geometry of any of the BRIDGEs may be altered toachieve desired performance criteria such as radial strength,longitudinal flexibility or stiffness, expansion ease, profile, surfacearea, mass and volume, and material selection. The elements of theBRIDGE may be porous, have through holes, or have a covering. Inaddition, the surface of the bridge may be textured, rough, and sharp orhave cleats or small pins integrated or attached. Each of the variousshapes and geometries may find its own specialized use in the treatmentof specific type of bone fractures.

[0043]FIG. 5 shows two states of a manually expandable BRIDGE device 51.The device consists of a coaxial shaft 52 and tube 53 arrangement.Attached to the distal end of the shaft 52 and the tube 53 is a braidedmesh tube BRIDGE 51. When the shaft 52 and tube 53 are moved opposite ofthe other by manipulating the proximal ends, the BRIDGE 51 expands 54 orcontracts 55. In this case, the BRIDGE 51 can be made of any structurethat expands and contracts such as a coil, splined-elements, etc. Thevarious methods of expanding and contracting these structures are, butnot limited to, push-pull, rotation, and balloon manipulation. In thistype of device, direct connection to either an electrical generator,laser, or monitoring system can be made. In addition, it be envisionedthat a device of similar nature be connected to a mechanical energysource, such as rotational or vibrational sources.

[0044]FIG. 6 shows a manually expanded BRIDGE 60 with an internal rod 61and compression nut mechanism 62. One end of the BRIDGE is fixed to oneend of the rod 63, while the other end 64 is allowed to move relative tothe rod. As the compression nut is tightened, it forces the end 64 ofthe BRIDGE to move, thus compressing the BRIDGE and forcing it toexpand. Using a customized tool, the compression nut is tightened andthe BRIDGE expanded until the desired affect is achieved. The nut canhave a locking mechanism, such as a lock washer or other means, tomaintain position. Alternatively, the nut and rod components can beexchanged for a bolt and nut or a bolt and internally threaded tubularrod. In any event, the expansion is caused by the relative movement of aa screw threaded mechanism.

[0045]FIG. 7 shows another manually expanded BRIDGE 70 with an internalrod 71 and compression element 72. One end of the BRIDGE is fixed to oneend of the rod 73, while the other end 74 is allowed to move relative tothe rod. As the compression element is pushed forward, it forces the end74 of the BRIDGE to move, thus compressing the BRIDGE and forcing it toexpand. The compression element is advanced and the BRIDGE expandeduntil the desired affect is achieved. The element can maintain itsposition utilizing mechanical friction or a detent mechanism. Othermeans of maintaining position are possible. The internal rod of themanually expanded BRIDGEs may be flexile or rigid. The expandingelements of the manually expanded BRIDGEs may utilize geometries such asthose discussed in FIG. 4

[0046]FIG. 8A & 8B show the use of a coil BRIDGE. The coil BRIDGE 81 isadvanced to the fracture in a stretched state with a diameter less thanits natural, unstretched diameter. When it is released from the deliverydevice 82, the coil BRIDGE expands to a state of greater diameter. As itexpands to a greater diameter 83 it naturally shortens in length. Thissimultaneously draws the fracture together and fixates the fracture.

[0047]FIG. 9A & 9B show the use of a braid BRIDGE. The braid BRIDGE 91is advanced to the fracture in a stretched state with a diameter lessthan its natural, unstretched diameter. When it is released from thedelivery device 92, the braid BRIDGE 93 expands to a state of greaterdiameter. As it expands to a greater diameter it naturally shortens inlength. This simultaneously draws the fracture together and fixates thefracture. The devices in FIGS. 8 and FIG. 9 can utilize other geometriesthat function sinilarly with similar results. In addition, shape memorymaterials that exhibit similar change of length and diameter may be usedin the construction of devices in FIG. 8 and FIG. 9.

[0048]FIG. 10 shows the BRIDGE 100 invention including the use ofexternal screws 101 that join the BRIDGE through the bone. This providesan extra measure of securement and strength.

[0049]FIG. 11 shows external plates 10 incorporated with thiscombination of external screws 111 and BRIDGE 112. There maybe fracturesthat require the additional stabilization that this combinationprovides.

[0050]FIG. 12A shows an implanted bridge 120 connected to an electricalgenerator 121 in order to expedite bone growth. The external screws inFIG. 10 can serve the dual purpose of adding securement and acting aselectrodes 122.

[0051]FIG. 12B shows a device 123 similar to that in FIG. 5 that isconnected to an electrical generator 124. In this scenario, the BRIDGEcan be used is in a temporary or permanent fashion. It may be desirableto remove the BRIDGE after the bone has healed.

[0052]FIG. 13 shows a expansion device 130 that uses a rubber sleeve orgrommet 131 that when compressed axially 132, expands radially 133.

[0053] It should be apparent that various modifications might be made tothe devices and methods by one of ordinary skill in the art, withoutdeparting from the scope or spirit of the invention.

What is claimed is:
 1. A device system for treating bone fracturescomprising: an expandable device for occupying space within bones; ameans of expanding the device; whereby the expanded device mechanicallyfixates the fracture.
 2. The device system of claim 1 wherein the meansof expanding the device is an inflatable catheter
 3. The device systemof claim 1 wherein the means of expanding the device is an axiallycompressed elastomeric grommet which expands radially when compressed 4.The device system of claim 1 wherein the means of expanding the deviceis the inherent spring force contained within the structure of theexpandable device
 5. The device system of claim 1 wherein the means ofexpansion is self-contained within the expandable device
 6. The devicesystem of claim 5, wherein the means of expansion is a relative movementof the opposing ends of the device
 7. The device system of claim 1,wherein the expanded device is substantially tubular
 8. The devicesystem of claim 1, wherein the expanded device has a substantiallycylindrical cross-section
 9. The device system of claim 1, wherein theexpanded device joins separated bone segments
 10. A method for treatingbone fractures comprising; utilizing an expandable device for occupyingspace within a bone segment; creating an access hole in bone; disposingthe structure upon a delivery device; inserting the structure within thebone segment; advancing the structure to the desired location within thebone segment; activating a portion of the delivery device in order tocause expansion of the structure.
 11. A method of claim 10, to furtherinclude deactivating the delivery device and removing from the bonesegment
 12. A method of claim 10, including the steps of utilizing adelivery device that has an expandable, inflatable portion whereon theexpandable device is disposed; and the expansion of the expandabledevice is accomplished by the inflation of the expandable, inflatableportion of the delivery device.
 13. A method of claim 10, including thesteps of utilizing a delivery device that has an expandable portionwhereon the expandable device is disposed; and the expansion of theexpandable device is accomplished by the compression of the expandableportion of the delivery device.
 14. A method of claim 10, wherein theexpandable devices are generally tubular in structure and plasticallydeformed in order to maintain expanded diameter
 15. A method of claim10, wherein the expandable devices are generally tubular in structureand are mechanically deformed
 16. A device for treating bonescomprising; an expandable tubular device, a delivery device; saidtubular device attached to delivery device; whereby the delivery deviceexpands the tubular device at treatment site, whereby the expandedtubular device joins bone segments.
 17. The device as in claim 16wherein said device is a tubular mesh.
 18. The device as in claim 16wherein said device has multiple splines.
 19. The device as in claim 16wherein said device is a coil.
 20. The device as in claim 16 whereinsaid device is a slotted tube.
 21. The device as in claim 16 whereinelectrical energy is delivered
 22. The device as in claim 16 wherein thedevice has a coating
 23. A device for treating fractured bonescomprising; a self-expandable tubular device; a delivery device; tubulardevice within the delivery device; said device combination advanced todesired location; said tubular device released from delivery device atdesired location; whereby the tubular device expands at treatment site,whereby the expanded tubular device joins and fixates bone fracture. 24.A device as in claim 23, wherein the stress applied to the bone from theradially expanded device enhances healing of the fracture.